Page 242 of Tony Thompson’s S.P. freight cars volume 1 on gondolas (and stock cars) shows
a single track under the Eagle Mountain (CA) iron ore loader, yet there are
four rails. I suspect this is because of a weight scale at the loader.
Is this true? I haven’t seen such an arrangement before. Does anyone
know of other examples? Thanks.
Mark Pierce
Can’t say 100% but it’s more likely to either be guard rails for some reason or gauntleted track… for some reason.
Even modern “strain gauge” scales that work electronically aren’t put where lots of dust will get on them or where they will be severely banged about… unless it is completely unavoidable.
The older scales mostly included a part called a “knife edge”. This gave the element of accuracy in the weighing (as I understand it). The knife edge was always protected from blows and dirt.
With smaller scales (for sack barrows and such) most places insisted that you walk round them not on them. this kept the maintenance cost down. You could collect a clout round the ear from the foreman if he caught you walking on the scale plate.
Scales do usually have an “at rest” and a “live” position. When anything is put on the scale, especially if it is a falling load, the scale should not be live. [As a principle I would expect the scale table to be lifted off of the knife edge to the “at rest” position rather than the knife dge dropped down from contact with the table].
That said… there have long been “rolling load” systems… for things like continuously moving coal trains.
This generalistaion is based on my Father having worked most of his life for the Board of Trade dealing with wieghts and measures. In the deep dungeons of his office block they had scales so accurate that you were not allowed within 5 feet of them because your body temperature would affect their accuracy. They were also stood on massive concrete plinths (in the floor) to iron out any vibration from traffic. The rooms were also temperature controlled way back in the 50s when such a thing was barely even dreamed of here.
[8D]
I think it’s far more likely that the extra rails are guard rails, just like the ones found in through truss bridges. If a car derailed under the tipple the last thing anyone would want is for it to take down the supporting structure.
Chuck (modeling Central Japan in September, 1964)
But track scales in rail yards often used gantlet track, so that a train could move past the scale house without being weighed.
The photograph I referred to shows a gondola being loaded and running on rails 1 and 3. If those were guard rails, it would be on rails 1 and 4 or 2 and 3.
Mark
Now you tell us! ( [:-,] )
99% of the time your conclusion would be correct… and this would be gauntletted track. Simple way to check (if the picture shws it) is the condition of the rail heads. If they all look the same - near enough - then the track is probably gauntletted and wheels are rolling on all four rails. If there is a significant difference one pair are probably gaurd rails… or one track isn’t being used.
I also wondered before… are there clear breaks in the rail heads (of one pair) that would indicate the gap between solid track and the rails on a scale table?
Another possibility occurs to me… the track may be gauntletted ready for a scale table either beyond the loading point or behind the camera. This would be more usual… as far as I am aware.
The simple thing is that you don’t want 40ton (or whatever) of coal regularly thudding down onto a scale - even when at rest - if you don’t have to have it. You also don’t want the dust… and, if it’s a coal with acid tendencies you don’t want any more of the risk of corrosion to expensive perts than essential.
Another thing is… where is the scale house/office? Is there any sign of this?
[:I] Just re-read the OP… it’s an iron ore loader not coal… Same thing applies as to weight… I would think that iron ore dust (and whatev
A scale in that location would also have some coal that would land on it causing a high reading for car weight unless it was cleaned frequently. It may only be pounds but scale test cars didn’t even have brakes so their weight wouldn’t be variable.
The photo has no date, but it is after 1957 because the 100-ton gondola (class G-100-1, numbered 345079) was built in (May?) 1958.
The tipple straddles a single track, is made of metal and uses I or H beams for vertical support, loading the ore directly overhead the gondola. There is an elevated control shed immediately adjacent to and partially under the tipple. The shed’s floor is almost as high as the top of the gondola. This must have been where the loader operator was stationed as it would give an excellent view to observe the filling of the gondola, but I can’t tell if there is weight-reading equipment in the shed.
It appears the cars were released singly from a cut to be moved without a locomotive (probably employing gravity to the stopped under the tipple for loading. The cars behind the loading gondola appear to be empty, so the flow of cars seems to be from the picture’s background to the foreground. At the immediate bottom (foreground) of the picture, rails 2 and 4 appear to be curving toward rails 1 and 3, respectively. This seems to be about a car length away from the loading gondola and where an apparent cement pad ends. There appear to be wood or metal strapping angling away from the base of the railhead outward at about 45 degrees to the cement base on all four rails for the length of the cement pad. I can’t see any joints in the rails, however.
The predominance of the evidence indicates the scale is under the tipple (gauntlet track immediately under tipple, elevated control shed, cement pad, cars handled singly). Also, the book’s author has since informed me there is a scale under the tipple.
Oh, those gondolas were unloaded by rotary machine as there were no bottom or side hatches on that gondola class.
Mark
Hi,
I believe it is highly unlikely that scales would be placed at the point of loading, due to the stress (constant usage) placed upon them by the car - whether empty or not.
I’ve been around rail facilities at 6 refineries (edible & petroleum oils) over the years and the scales were always on a track used exclusively for the weighing process. The cost of scales, as well as scale maintenance (re-calibration) is expensive.
Hope that helps!
Mobilman44
Hi Mark
There is no way a scale would be placed under a loader. The gauntleted track is for the differing hights of the cars being loaded and the angle of the discharge chute. A low sided gondola would be placed anywhere from a half foot to a foot and a half farther away from the angled chute than a high sided hopper. I load trucks with gravel from a chute that comes out at 45 degrees and to get the loads centered the truck is lined for its hight. If the tipple is multiple track the main hopper is usualy centered and angled chutes fill cars on the outside tracks. If a car is loaded 6 to 8 inches from center with that much weight it becomes very unstable. You cant move the tipple so the only alternative is to move the car.
Hope this helps
Pete
The ore was dumped from directly overhead. There were no angled chutes here. Thus, there would have been no need to move the center of the car from directly under the chute. The mystery remains, for me at least.
Mark